Rocking amusement device



1970 H. M. HATFIELD ROCKING AMUSEMENT DEVICE Filed 001;. 30, 1967I/vvs/vrae K525527111. Har /51.0

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United States Patent 3,494,613 ROCKING AMUSEMENT DEVICE Herbert M.Hatfield, Downey, Calif., assignor to Jamison, Inc., Torrance, Calif, acorporation of California Filed Oct. 30, 1967, Ser. No. 679,006 Int. Cl.A63g 31/02 US. Cl. 272-1 6 Claims ABSTRACT OF THE DISCLOSURE Anamusement device of the type in which a rockable member is supported byone or more upright helical or coil springs. The upper end of eachhelical spring is secured to the rockable member by means of a helicalspring fixed to a cylindrical tube forming a male member and the lowerend of each spring is secured to a base by means of a flanged lockingnut.

Background of the invention This invention relates generally to rockableamusement devices of the type employing one or more upright helicalsprings, and, more particularly, to specific arrangements for mountingthe springs to the rockable portions and to the bases of the legs of thedevices, and also to improved bases for engaging different grades ofground.

There are various types of childrens playground equipment comprisingplatforms ofditferent configurations which are supported by uprighthelical or coil springs for rockable movement. Such playground equipmentcomprises either generally fiat platforms which accommodate severalchildren, and are supported generally by three helical springs, orsingle seated devices having a configuration, for example, of a rockinghorse, and are supported by a single helical spring. In both cases, ithas been the general practice to support each helical spring in agenerally vertical position with the upper end of the spring connectedto the rockable device, and the lower end of the spring connected to abase member secured to the ground, by placing a metal bar across theupper and lower convolutions of the springs and by tightening down nutson bolts which pass through the bars.

This type of a helical spring mounting arrangement has the disadvantagethat oftentimes the bar which secures the upper and lower portions ofthe helical spring to th rockable member and base, respectively, yieldswhen the nut is threaded tightly upon the bolt, thus resulting in anassembly which is capable of slipping. Also, the bars generally employedfor mounting helical springs have only about 10% bearing surfaceengaging the end convolutions of the springs. As a consequence, theconventional coil spring mounting arrangement for rocking amusementdevices sometimes becomes loosened, thereby creating a safety hazard andrequiring reassembly of the spring to the rockable platform or base.

Summary of the invention It is an object of the present invention toprovide a rockable playground device having an improved helical springmount A further object of the invention is to provide an improvedrocking amusement device employing three coil spring-type legs, and animproved base for the legs which is capable of conforming to differentgrades of ground supporting the amusement device.

According 'to the principal aspect of the present invention, there isprovided a rockable amusement device having one or more helicalspring-type supporting legs. The helical spring is connected at itsupper end to the lower part of the rockable member of the amusementdevice by threading the spring onto a threaded male eleice ment whichcomprises a tube having a convolution of a second helical spring securedthereto. The lower portion of the helical spring is afiixed to the baseof the leg by means of a locking disc. The disc has a circular body witha flange extending outwardly from a portion of the circular peripherythereof. The circular body of the locking disc is disposed within thecylindrical channel in the helical spring with the flange resting uponthe upper surface of the convolutions. The disc is threaded downwardlyto the bottom of the spring until the flange rests upon the uppersurface of the lowermost convolution. The locking disc is then securedby suitable fastener means to the base. By use of the locking dischaving a flange as above described, a substantially greater bearingsurface is provided for engaging the lower convolution of the coilspring than is provided by the bar lying across the end convolution of ahelical spring in a conventional helical spring mount.

In the preferred embodiment, there is also provided 2. lug dependingdownwardly from the lower surface of the locking disc which engages anopening in the base so as to prevent rotation of the disc with respectto the spring and, thus, overcome the slippage problem which exists inthe conventional helical spring mounts.

In the preferred embodiment of the invention, wherein the rockablemember of the amusement device is supported by a plurality of verticallyinclined legs, the base of each of the legs includes a cylindrical tube,the upper end of which is connected to the coil spring of the leg, andthe lower end is embedded in the ground or a concrete footing in theground. A plate adapted to engage the upper surface of the groundincludes a cylindrical sleeve having a bore therethrough. Thelongitudinal axis of the bore is disposed at an angle, when the plate ishorizontal, which is substantially equal to the angle of the legs. Thecylindrical tube of the base is slidably mounted in said bore. Byrotating the plate about the tube, the plate may be positioned toconform to different gradings of ground upon which the amusement deviceis supported Further objects, aspects and advantages of the inventionwill become apparent from the following description taken in connectionwith the accompanying drawings, wherein:

Brief description of the drawings FIGURE 1 is a side elevational view ofthe preferred rocking amusement device of the invention;

FIGURE 2 is an enlarged vertical section taken along line 22 of FIGURE 1showing one of the legs of the amusement device;

FIGURE 3 is an enlarged vertical section taken along line 33 of FIGURE2, showing the mounting arrangement for the upper portion of the helicalspring of the FIGURE 4 is an enlarged sectional view taken along line 44of FIGURE 2, showing the locking disc for securing the lower portion ofthe helical spring to the base of the leg; and

FIGURE 5 is a perspective view of the locking disc, showing the bottomthereof.

Description of the preferred embodiment Referring now to the drawing indetail, there is illustrated in FIGURE 1 a rocking amusement device,generally designated 10. The device includes a relatively flat circularplatform 12 supported preferably by three legs, each generallydesignated 14. A cylindrical wall 16 is welded to the top of theplatform 12. Rails 18 extend around the major portion of the upper edge19 of the Wall 16. The wall 16 and rails 18 provide a compartment inwhich children may play on top of the platform 12. It is to beunderstood that the above described platform is given by way of exampleonly, and not by limitation.

20, and an upright coil or helical spring 22. Since a portion of thelegs are formed-of the helical springs 22, it can be readily appreciatedthat the platform 12 may be rocked in a generally horizontal plane.

In the preferred embodiment of the invention, the three legs 14 aresubstantially equidistant from each other, and extend at an angledownwardly-and outwardly from the bottom 24 of the platform with theirlongitudinal axes converging substantially to a common point above thecenter ofthe platform. It is preferred that the legs extend at an angleof about 75 with respect to the ground 25 to provide maximum stabilityof the platform 12, yet permit the platform to be readily rocked bychildren.

Reference is now made to FIGURE 2 which illustrates in detail one of thelegs 14 of the device 10, the other legs being identical. The base 20 ofthe leg includes a cylindrical tube 26 having its lower end embedded ina concrete footing 28 in the ground 25. A generally flat circular plate30 is welded to the upper end of the tube 26. The lower.- mostconvolution 32 of the helical spring 22 is supported by the uppersurface 34 of plate 30.

A mounting plate 36 is welded to the bottom 24 of platform 12 beneaththe cylindrical'wall 16, thereby providing additional support for thewall. A cylindrical tube 38 is welded to the plate 36. The tube 38 hasan outer diamter less than the inner diameter of the convolutions of thespring 22 so as to be capable of receiving the upper end of the spring.

As seen in FIGURE 2, the longitudinal axes of the tube 38, the helicalspring 22 and the tube 26 are coaxial and thus disposed at an angle ofabout 75 with respect to the horizontal ground 25.

The upper end of the spring 22 is mounted to the lower part of theplatform 12. by welding a convolution 40 of a second spring on the outersurface of the tube 38, as best seen in FIGURE 3. The convolution 40 hasgenerally the same dimensions and configuration as the convolutions ofthe spring 22, except that the spacing between the ends 42 and 43 of theconvolution 40 along the longitudinal axis of the leg is slightly lessthan the spacing between the upper convolutions 44 and 45 of the spring22. It can be appreciated that by the provision of the convolution 40 onthe outer surface of the tube 38, there is provided a threaded maleelement.

When the spring 22 is initially being assembled to the platform 12, thespring is threaded onto the tube 38 with the upper convolution 44 of thespring engaging the convolution 40 as illustrated in FIGURE 3. Since theaxial be readily appreciated that the convolution 40 could be extended,if desired, to a second convolution for further frictional engagementwith the helical spring 22.

The lower portion of the spring 22 is secured to the plate 30 by meansof a locking disc, generally designated 50. The disc includes a circularbody 52 with generally flat upper and lower surfaces 53 and 54,respectively. The body 52 has a diarneter slightly less than the innerdiameter of the convolutions of the spring 22. I

The disc 50 includes an outwardly extending flange 56 which extendsabout only a portion of the periphery of the circular body 52, as bestseen in FIGURE 4. The flange 56 slopes from one end thereof 58 adjacentto the upper surface 53 of the body 52 downwardly toward the othenend 60of the flange which is closer to the lower surface 54 ofthe body. Theslope of the flange 56 is substantially equal to the slope of theconvolutions of the 4 Spring 22 so that when the disc 50 is insertedinto the in terior of the helical Spring 22, the entire flange 56 willrest upon the upper surface of the convolutions of the spring and engagethe same in a similar fashion to a threaded male member engaging athreaded female member.

It is preferred that the flange'56 extend at least 180 about theperiphery of the circular body 52 of the locking disc to provideadequ'atebearing surface 'for engaging the upper surface of thelowermost convolution 32 of the Spring 22. The flange, however, mustextend only partially about the periphery of the body 52 in order topermit the disc 50 to be inserted into the interior of the helicalspring 22 and to be threaded therein down to the lowermost convolution32. In the preferred embodiment of the invention, the flange extendsapproximately 210 about the periphery of the body 52 of the lockingdisc, which permits the disc to be readily inserted into the spring 22,yet provides a substantial amount of bearing surface for engagement ofthe lowermost convolution 32 of the spring.

As best seen in FIGURE 2, the convolution 32 of the spring 22 isgenerally normal to the longitudinal axis of the spring so that almostthe entire lower surface of the convolution 32 engages the upper surface34 of the plate 30 of the base. Since the convolution 32 is generallyynormal to the longitudinal axis of the spring, the end 66 of theconvolution contacts the lower surface 67 of the next adjacentconvolution 68. As a consequence, when the locking disc 50 is threadeddown to the lower end of the spring 22 so that the lower surface 54engages the upper surface 34 of plate 30, the leading edge of the flange56 adjacent to the end 60 becomes wedged between the lowermostconvolution 32 and the adjacent convolution 68.

In order to prevent the disc 50 from unthreading from the convolutionsof the helical spring 22 when seated against the plate 30, there isprovided a lug 70 which depends downwardly from the lower surface of thecircular body 52. An opening 72 is provided in the plate 30. The openingis so located that when the disc 50 is threaded to the bottom of thespring 22, the lug 70 will engage into the opening 72, therebypreventing any further rotation of the disc.

The disc 50 is secured to the plate 30 when threaded to the lower end ofthe spring 22 by means of a bolt 76 fixed to the plate 30 and extendingupwardly through a central bore 78 in the disc. A look washer 80 ispositioned over the upper end of the bolt 76 and a nut 82 is threadedonto the bolt to force the flange 56 of the locking disc downwardly uponthe upper surface of the lowermost convolution 32 of the spring, therebysecurely clamping the lower end of the spring 22 to the base 20.

The base 20 includes a circular plate generally designated 86, having adownwardly curved top 87 and a peripheral annular flange 88 whichengages the ground 25 to provide support for the tube 26 in addition tothat derived by the embedding of the tube into concrete 28. A sleeve 90is positioned in a central bore 92 extending through the top 87 andsecured to the plate by welding or the like. The sleeve 90 has a bore 94therethrough, the longitudinal axis of which isdisposed of at an angle,when the plate is horizontal, which is substantially equal to the angleof the leg 14, and consequently the tube 26.

I The tube 26 is 'slidably mounted within the bore 94. A

' may still be positioned so as set screw 96 mounted in the sleeve 90engages the outer surface of the tube 26. By this construction the plate86 may he slid longitudinally on the tube 26 and may be rotated aboutthe tube in order to conform to different grades of ground upon whichtheamusement device 10 is mounted. As a consequence, the device 10employing bases 20 as described herein, may be mounted on slopingground, and the flange 88 of the plate 86 of each leg to firmly seatagainst the surface of the ground.

While the preferred embodiment of the invention has been disclosedherein as constituting a platform employing three legs 14, it isunderstood that the spring mounting arrangement of the invention may beemployed with rocking amusement device employing as few as one leg ormore than three legs, and could be utilized in any other type ofassembly wherein it is desired to securely mount the ends of a helicalspring.

Although I have herein shown and described my invention in what I haveconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of myinvention, which is not to be limited to the details disclosed herein,but is to be accorded the full scope of the claims so as to embrace anyand all equivalent structures and devices.

I claim:

1. A rocking amusement device comprising: a rockable member; at leastone leg extending downwardly from said member; said leg including anupright helical spring and a base having a longitudinal axis coincidentwith a longitudinal axis of said helical spring and extending therefromand adapted to 'be secured to the ground; first securing means includinga cylindrical tube fixed to the bottom of said rockable member with itslongitudinal axis coincident with the longitudinal axis of said leg, theouter diameter of said tube being less than the inner diameter of theconvolutons of said spring; a convolution of a second helical springhaving generally the same dimensions as that of the upper convolutionsof said first mentioned spring, said convolution of said second springembracing said tube and being fixed thereto to provide a threaded maleelement; and the upper convolution of said first mentioned spring beingthreaded onto said male element, second means securing the lower part ofsaid spring to said base; said second securing means comprising alocking disc, said disc including a circular body having a diameter lessthan the inner diameter of the convolutions of said spring, a flangeextending outwardly from only a portion of the circular periphery ofsaid body, said body being disposed within the cylindrical channel inthe helical spring defined by the inner periphery of the convolutionsthereof with said flange threadably engaging the upper surface of theconvolutions of the spring, and fastener means releasably securing saiddisc and, hence, said spring to said base when said disc is threaded tothe lower end of said spring and said flange engages the upper surfaceof the lowermost convolution of the spring.

2. A device as set forth in claim 24 wherein said body has a lowersurface, a lug depending downwardly from said lower surface of saidbody, an opening in said 'base, said lug engaging said opening when saiddisc is threaded to the lower end of said spring.

3. A device as set forth in claim 1 wherein said flange extends morethan 180 about the circular periphery of said body; said body havingupper and lower surfaces, a lug depending downwardly from said lowersurface; an opening in said base, said lug engaging said opening whensaid disc is threaded to the lower end of said spring; and said flangesloping from one end thereof adjacent to said upper surface of said bodydownwardly toward the other end thereof adjacent to said lower surfaceof said body,

the slope of said flange being substantially equal to the slope of theconvolutions of said spring.

4. A rocking amusement device comprising: a rockable member; at leastone leg extending downwardly from said member; said leg including anupright helical spring and a base adapted to be secured to the ground;first means securing the upper part of said spring to said member;second means securing the lower part of said spring to said base; saidsecond securing means comprising a locking disc, said disc including acircular body having a diameter less than the inner diameter of theconvolutions of said spring, a flange extending outwardly from only aportion of the circular periphery of said body, said body being disposedwithin the cylindrical channel in the helical spring defined by theinner periphery of the convolutions thereof with said flange threada'blyengaging the upper surface of the convolutions of the spring, andfastener means releasably securing said disc and, hence, said spring tosaid base when said disc is threaded to the lower end of said spring andsaid flange engages the upper surface of the lowermost convolution ofthe spring, wherein, a plurality of said legs extends at an angledownwardly and outwardly from said rockable member, said legs beingsubstantially equidistant from one another and having longitudinal axes;and said longitudinal axes of said legs converging to substantially acommon point above said member.

5. A device as set forth in claim 4 wherein there is provided three ofsaid legs, and the angle of each of said legs with respect to ahorizontal plane being approximately 6. A device as set forth in claim 4wherein each of said bases of said legs includes: a cylindrical tubebeing adapted to have one end thereof embedded in the ground at saidangle; a plate adapted to engage the surface of the ground; said plate,including an upright sleeve, said sleeve having a cylindrical boretherethrough with the longitudinal axis thereof being at an angle, whensaid plate is horizontal, which is substantially equal to said firstmentioned angle; said tube being slidably mounted in said bore, wherebysaid plate is rotatable about said tube; and means for releasablysecuring said plate to said tube.

References Cited UNITED STATES PATENTS 326,721 9/1885 Crandall 272-52 X1,956,846 5/ 1934 Williams. 2,184,453 12/ 1939 Hayes 272-78 2,949,298 8/1960 Speelman 272-60 X 2,996,205 8/1961 Smith 272-66 X D 198,923 8/ 1964Mitchell.

3,292,924 12/1966 Wormser et a1. 272-54 FOREIGN PATENTS 330,206 10/ 1935Italy.

ANTON O. OECHSLE, Primary Examiner ARNOLD W. KRAMER, Assistant ExaminerUS. Cl. X.R. 267-1

